[foh-tuh-peer-ee-uh-diz-uh m] /ˌfoʊ təˈpɪər i əˌdɪz əm/
the response, as affecting growth or reproduction, of an organism to the length of exposure to light in a 24-hour period.
the response of plants and animals by behaviour, growth, etc, to photoperiods
1920, from photoperiod (1920, from photo- + period) + -ism.
photoperiodism pho·to·pe·ri·od·ism (fō’tō-pĭr’ē-ə-dĭz’əm) or pho·to·pe·ri·o·dic·i·ty (-pĭr’ē-ə-dĭs’ĭ-tē)
The response of an organism to changes in its photoperiod, especially as indicated by vital processes.
photoperiodism (fō’tō-pîr’ē-ə-dĭz’əm) also photoperiodicity
The response of an organism to changes in its photoperiod, especially as indicated by vital processes. For example, many plants exhibit photoperiodism by flowering only after being exposed to a set amount of daylight, as by requiring either a long or short day to flower. Plant growth, seed germination, and fruiting are also affected by day length. Photoperiodic responses in plants are regulated by special pigments known as phytochromes. In animals, migration, mating, amount of sleep, and other behaviors are also photoperiodic. In many animals, photoperiodism is regulated by the hormone melatonin.
[foh-tuh-fil-ik] /ˌfoʊ təˈfɪl ɪk/ adjective 1. of or relating to an organism, as a plant, that is receptive to, seeks, or thrives in light.
[foh-tuh-fil-ik] /ˌfoʊ təˈfɪl ɪk/ adjective 1. of or relating to an organism, as a plant, that is receptive to, seeks, or thrives in light. /fəʊˈtɒfələs/ adjective 1. (esp of plants) growing best in strong light
[foh-tuh-foh-bee-uh] /ˌfoʊ təˈfoʊ bi ə/ noun, Pathology. 1. an abnormal sensitivity to or intolerance of light, as in iritis. 2. an abnormal fear of light. /ˌfəʊtəʊˈfəʊbɪə/ noun 1. (pathol) abnormal sensitivity of the eyes to light, esp as the result of inflammation 2. (psychiatry) abnormal fear of or aversion to sunlight or well-lit places n. […]
[foh-tuh-foh-bik] /ˌfoʊ təˈfoʊ bɪk/ adjective 1. of or relating to an organism that avoids light. photophobic pho·to·pho·bic (fō’tə-fō’bĭk) adj.